Got mine from the dealer about a year after I got the car. They were having a special on the steelies so I got all 4 for $200 (CA). I would expect that with the Pro no longer being made, the steelies might be a bit more.
Have you tried checking with the local auto wreckers? If they have a Pro - of any kind, as long as it's 99 through 03 I believe - the steelies should fit.